What repairs your DNA when it gets damaged?
Thus, enzymes known as DNA glycosylases remove damaged bases by literally cutting them out of the DNA strand through cleavage of the covalent bonds between the bases and the sugar-phosphate backbone. The resulting gap is then filled by a specialized repair polymerase and sealed by ligase.
What types of DNA damage are repaired by homologous recombination?
Homologous recombination (HR) faithfully repairs complex DNA damage including DNA double-stranded breaks (DSBs) by referencing an intact donor template in the form of the sister chromatid, a homolog, or an ectopic sequence.
What is homologous DNA?
Homologous Recombination Homologous recombination is a type of genetic recombination in which nucleotide sequences are exchanged between two similar or identical molecules of DNA.
What can homologous recombination be used for?
Homologous recombination (HR) is critical both for repairing DNA lesions in mitosis and for chromosomal pairing and exchange during meiosis. However, some forms of HR can also lead to undesirable DNA rearrangements.
Which vitamins help repair DNA?
Vitamin B12 and folate have also been found as essential for DNA metabolism. In short folic acid and B12 are required for the maintenance of DNA conformation and methylation patterns.
Which DNA polymerase is involved in DNA repair?
Nucleotide excision-repair uses DNA polymerases delta or epsilon to resynthesize the bases removed during repair of pyrimidine dimers and other bulky adducts in DNA. Similarly, mismatch-repair of replication errors appears to involve DNA polymerases delta or epsilon.
Can hairpin DNA or supercoiled plasmid be used to study DNA damage?
Unfortunately, neither hairpin DNA nor supercoiled plasmid is a good model system for studying DNA damage in vivo. Povirk et al. has shown that in vitro, partial intercalation is required for BLM-mediated ds-DNA cleavage in reconstituted nucleosomes (44).
Which radiomimetic DNA-cleaving agents cause DNA damage and mutagenesis?
DNA damage and mutagenesis by radiomimetic DNA-cleaving agents: bleomycin, neocarzinostatin and other enediynes. Mutat. Res.
Does β-cyclodextrin reduce the affinity of CD-BLM for DNA?
The reduced overall DNA cleavage ability could be attributed to the β-cyclodextrin group, which would be expected to reduce the affinity of CD-BLM for DNA. It might also be related to a slower rate to generate activated BLM and/or a faster degradation rate of the activated species, CD-BLM-Fe(III)-OOH.